In fluid systems it is often desirable to provide for controllably passing fluid to selected locations in response to operating of controls. The greater the number of locations relative to the number of pumps and controls, the greater is the flexibility of the system.
An example use of such a fluid system is an excavator which has left and right track motors for locomotion and a plurality of work elements connected to the fluid system. In the use of an excavator, it is desirable to provide adequate fluid and pressure selectively to the work elements both while the vehicle is stationary and while the vehicle is moving. Further, it is also desirable to provide selective combining of pumps to a selected work element and to provide for more rapid movement of fluid from one of the work elements to tank.
These problems are not solved in the heretofore utilized excavators which generally connect the plurality of pumps in parallel relationship with the working elements.
The present invention is directed to overcoming one or more of the problems as set forth above.
According to the present invention, a fluid system has a plurality of pumps, left and right track motors, and a plurality of work elements. First elements are provided for controllably delivering fluid from a first plurality of said pumps to the left track motor and for controllably bypassing the left track motor and delivering fluid from at least one of the first plurality of pumps to a separate work element. Second work elements are provided for controllably delivering fluid from a second plurality of said pumps to the right track motor and for controllably bypassing the right track motor and delivering fluid from at least one of the second plurality of pumps to a separate respective work element.